


Shared Burden

by kansas_byrne



Category: Supernatural
Genre: Alternate Universe - Canon Divergence, Blood, Blood Kink, Bloodlust, Canon-Typical Violence, M/M, Mark of Cain, Not Beta Read, Wincest - Freeform, hematolagnia, unsafe sexual practices, urge to murder all the things from both brothers
Language: English
Status: Completed
Published: 2018-01-23
Updated: 2018-01-23
Packaged: 2019-03-08 15:36:56
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 3,190
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13461276
Author URL: https://archiveofourown.org/users/kansas_byrne/pseuds/kansas_byrne
Summary: Sam is now bearing the Mark of Cain with Dean, but doing it has some side effects that neither of them bargained for.





	Shared Burden

Nothing had worked so far… nothing but _the spell._ Cas and Charlie had found the thing together, and it was such a phenomenally bad idea that there was nothing except do it immediately. The spell allowed both brothers to bear The Mark together, so that Dean wasn’t so overwhelmed. That was the theory, anyway. 

The practice was that instead, _both_ of them were overcome with a need to kill things, each one boosting the other’s bloodlust like a feedback loop, and so they cut a bloody swath through anything and everything that happened across their path; werewolves, angels, vampires, whatever. It also meant that they couldn’t be away from each other for too long without getting antsy. When they got back into each other’s presence, the rest of the world could fade away for all either of them cared. 

It was Sam who started it. Whenever it gets brought up later, Dean will always say that, as if he was ten years old and trying to justify why the two of them had felt the need to wake John up from his hangover with their yelling. Sam did it. He started it. Sam tells a different story, of course, but what can you do, little brothers tattle. 

They’d ridden for twelve hours to get to a truck-stop of a town in the middle of nowhere because four girls had gone missing in the last month, each one mutilated in the same way, from the inside out. The entire drive so far had been in silence. Dean would put music on, and then realize that he couldn’t hear Sam breathing, so he’d turn it off, and then Sam would make this sighing noise. It wasn’t the usual; an annoyed exhale signifying when Dean was getting on his last nerve. instead it was a long, breathy thing. It sounded relieved as if he had also hated not being able to hear Dean breathing, but there was another timbre to it that made Dean very uncomfortable. So he just drove the car and listened to Sam breathe, The Mark throbbing with what he suspected was Sam’s heartbeat. 

Finally, the car rolls up to the only motel for miles around. It’s the usual mix of seedy and weird, making Dean wish he had a gallon of hand sanitizer and some bleach. The room also only has one queen sized bed, squished into a room so small that the bed has to be up against a wall to fit. 

“Last one they had,” Sam had said (too) cheerfully as he came out of the office with the key. Dean narrowed his eyes at that, but accepted it. 

So they have to share. It isn’t the first time, but it’s the first time since his arm started doing this throbbing business. Since he couldn’t bear to not be near Sam. But Sam sees cheerful and unconcerned, pointing out that there is a steak place nearby in a blatant manipulation to distract Dean. It works, of course. He eats too much and drinks until his head is a little fuzzy, trying to drown out everything. His brain feels too full somehow, like he can’t stop thinking, can’t stop wanting something that’s buzzing under his skin, making him feel edgy and slightly aroused. 

He turns in first, grabbing the wall side of the bed first while Sam showers. The wall is right next to the bathroom, and the thrum of the water has Dean in a floating, near sleep state when Sam finally comes back. The bed dips alarmingly under Sam’s tower of muscle, and then he’s wriggling around next to Dean, trying to get comfortable. Dean freezes, silently wishing that he’d worn more than just his boxer-briefs to bed. Sam nestles impossibly close, finally finding the best place to lie down, apparently. His breathing evens out, letting out that sigh again, and Dean’s carefully constructed fort of calm shatters in one breath. 

Sam sleeps calmly, nestled close to his brother who lies stock still with his hands pressed against the wall, The Mark throbbing on his arm, and his cock hard as a rock. He’s unable to stop thinking about being pressed against it by Sam, holding him fast and whispering in his ear. He’s vile, he’s vile and he wants it. He finally passes out in the deep hours of the night, exhausted from circling down the drain of self disgust and intense need. 

The blue light of too-fucking-early wakes him up before Sam. He rarely comes to so slowly, but he’s warm and comfortable, and he hasn’t felt this right in so very long. When his head clears more, he realizes that Sam’s arm is draped over him possessively, along with one leg. The posture presses his groin up against Dean’s ass, and distantly he’s impressed with how not-surprised he is that Sam is rock hard. Shutting his eyes against the light, he tries to just ignore it. He doesn’t want it. He isn’t aching. One hand strays to his crotch, and he lightly brushes a finger up his cock through his briefs. Sam stirs, in the twilight of wakefulness where reality could still be a dream, and starts gently rocking himself against Dean. Dean sees stars. He wants so hard he can feel The Mark give a powerful throb, and then Sam wakes up with a throaty moan. 

Dean flails around in an attempt to get the fuck out of bed before he gives in to what he desperately wants: rocking his hips backwards and rubbing himself against the hard length of Sam’s cock. Sam falls out of bed with a startled curse as Dean pushes his way out and into the bathroom for a long shower that does nothing to calm the storm raging under his skin. Under both their skins. 

Neither of them talk about it. The Mark pushes at them irritably, and so neither of them talk about anything else either, snapping angrily at each other for small things. They fall back into research, and it takes days. 

Every night, Dean dreams about his brother taking him against that wall, or doesn’t sleep, hyper aware of Sam next to him. Sam doesn’t fare well either, circles under his eyes and tension around his mouth telling Dean that he isn’t the only one lying awake inches from what he wants. What he needs. 

Research finally turns up something that sounds like it’s out of a Lovecraft book, which is not at all encouraging. They figure that this small town of fuckville has a thriving cult, worshipping some ancient creature masquerading as a goddess. And she needs a vessel, but like an angel, if she doesn’t have the right one, she'll rip right through it. She’s known for transforming her followers into creatures. Sam reads the research in the car. 

“They need a lot of room for this, I gather, and that abandoned farm we passed on the way in has a huge barn.” He scrolls down the page, his face lit blue in the dark. 

“She’s supposed to grant her followers powers, along with a new shape,” he mentions offhandedly. The fucking tone of his voice makes Dean want to punch him. 

“What powers?” Dean says irritably, rubbing his arm. Sam just shrugs, his eyes glued to the movement. 

“I don’t know, it doesn’t say. Anyway, we will need to be careful, cause it doesn’t talk about what ‘new shape’ means either. They could turn into werewolves for all I know.” Sam closes the laptop and looks out the window at the crisp winter sky. 

There’s silence for a few minutes, but Dean can hear Sam revving himself up. 

“Dean,” Sam starts, and Dean shakes his head. 

“No. No, Sammy, we are not having this conversation.” Dean agitatedly shifts in his seat, his hands gripping the wheel hard enough to turn white, and just barely able to stop at the only damn stop light in town. 

“And what conversation is that, Dean?” Sam turns so his back is against the door so he can look at Dean. 

Dean is _not_ looking back. Just waiting for the light to change. He taps his fingers on the steering wheel. “I don’t know. Whatever… conversation you were going to start.” 

Sam grits his teeth. “Dean…” 

“No, Sam! This is not something we talk about. “ Dean punches it seconds before the light goes green. He shouldn’t be speeding out in hicksville, but the sooner they can go fuck up this bitch’s day, the sooner he can get ragingly drunk. And find a waitress. He’ll just have to ignore the skin crawling when he’s not near Sam. It’s fine. A drink and a fuck will fix it. With a girl. He steadfastly ignores the whisper in the back of his mind that says _and not with your brother._

Luckily, they find the place sooner rather than later, and park Baby off the side of the road. They’ll have to hoof it in the dark, but her engine is loud, and it’s disturbingly quiet out here. As it is, the moon is bright and the snow glitters beneath it, so getting there carefully takes some doing, even with most of this land being forest. After what seems like ages, they come up to the back of the farmhouse. The barn is lit, and they can hear many voices chanting, and the sound of someone crying. 

The barn hasn’t been tended to in a long time, so they come up to the back of it and peek through the warped wood to the inside. A least a dozen, maybe more chanting cultists surround a hogtied teenager in the middle of a summoning circle. 

Dean opens his mouth, and Sam nods firmly, whispering “Vessel number five.” 

The girl in the middle of the floor wails as she stretches, her limbs and jaw and bones cracking, lengthening, transforming. The restraints snap, and she rises. With a wave of her hand, her postulants fall to the floor, screaming in agony as she changes them into monsters; teeth and claws and tusks, hard to look at without feeling the edges of sanity fray and unravel. They should run. Run, and never look back. 

They kick in the door. 

Blood. 

Screaming. The Mark loves it, edging into Dean’s consciousness, he won’t quite go the extra step, but resistance while fighting these people is hard. The Mark makes him feel so good about killing. 

Blood and pain, and The Mark egging him on. He’s covered in it, he’s glorying in it. Through a haze, he’s dimly aware of other people, their shapes are fuzzy and frightening, but Sam burns brightly in his vision. He aches for him. In sync, they move so that their backs touch, a conjoined killing machine, seamlessly gutting and decapitating, right until the goddess throws Sam across the room. He lands with a thump. Dean hears a cracking noise, and then he gives in without a thought, letting The Mark take over. 

When his vision clears, he’s kneeling over the body of the girl the goddess was inhabiting. He is coated in blood, elbow deep in her corpse. There’s blood on his face, on his clothing, in his hair, and he’s hard as a rock. The Mark is like a drum, insistently beating; a steady thrum like a heart. A heart…. 

Dean casts around, looking for Sammy, screaming for him. A low groan comes from the corner, and then it’s hot-cold-marco-polo as The Mark leads him like a beacon to his brother, lying in a pile of farm equipment. He’s getting up from the floor, and he has blood spattered over him. Dean gets into his space, running his hands over Sam’s body in a panic, he has to make sure. He heard that horrible noise, that cracking, but he’s not hurt, he’s fine, Dean bites back tears of relief...Sam makes a sound in the back of his throat. Dean finds that he’s running been his hands over the mark without realizing it, over and over. He stops moving, the hair on the back of his neck standing on end. A shiver runs down his spine, and he wishes he could stop it. He steps back one step. 

“There’s so much blood,” Sam murmurs, looking over Dean. There is. He’s _drenched_ in gore, as if he’s been bathing in blood. 

Sam’s pupils are blown. Dean licks his lips and Sam tracks the movement with his eyes. He looks so stoned. Dean thinks he should back away. He doesn’t want to. Sam’s lips curve, and the predatory tilt to it makes Dean shudder again. 

“So. Much. Blood.” Sam says again, stepping right into Dean’s space. His lips are inches from Dean’s. Dean should...he should step back. The Mark starts throbbing, and they both groan at the same time. Sam leans forward slowly and deliberately. He slips a hand behind Dean’s head and pulls him in for a kiss. Dean opens his mouth for Sam, letting him in, and the surrender is the first good thing he’s felt in a long time. The Mark beats in time with their shared heartbeats, and Dean can see Sam feels that too. 

Sam whispers against Dean’s lips, “I want you.” Dean nods, babbling something about getting to the motel. He’s not entirely sure what it is he did say, but Sam sees to have understood it, because he shakes his head. 

“No. I want you right. Now.” He runs a hand down the length of Dean until he gets to his crotch, which he palms in one gigantic hand. Dean groans and bucks against it. The voice in the back of his head rails against him, _sick, perverted, leave your brother alone_ , but instead he lets Sam pull him down onto the floor. 

There’s a large pool of blood here, but it only seems to excite Sam. He pushes Dean back onto the floor, into it. It soaks into the back of his shirt, what little isn’t already wet, making a squishing noise as Sam leans over him. He brushes his hands gently over Dean’s face before kissing him again, a deep and possessive thing that leaves Dean shaking and reaching for Sam. He pulls Dean’s hands up over his head, and pins them to the floor, lying on him. Sam’s weight is delicious, his cock gloriously hard and he’s gently thrusting, rubbing it against Dean while he starts biting. He bites Dean’s ear, and his neck, impatiently pulling at Dean’s shirt until the buttons pop off, until the blood soaked undershirt is the only thing between Sam’s mouth and Dean’s skin. He groans at the sight, and lets Dean’s hands go, pulling him up just enough to force the wet fabric up and off, exposing him to the cold. Sam looks him over, his eyes feasting. Dean lies back into the pool of blood and deliberately, slowly, stretches. 

Sam snarls, hooking his thumbs under Dean’s waistband, and he tries to tell him to stop, to wait, let him unbuckle at least, but Sam just _yanks_ with an animal growl, and he yelps in pain as his jeans and briefs are pulled down past his knees. Sam reaches out and strokes one finger up the length of Dean’s cock, fixated. Then he reaches out as if in a trance, and takes Dean’s hand and places it there. 

“Show me,” Sam whispers. His is covered in blood, sticky and gross, and he would care, he _would_ , but Sam’s eyes are nearly black with desire, and he’s watching while he unbuckles his own pants. So Dean does it, and fuck, it feels good. The Mark loves it, raging through his blood for more. He fucks up into his hand as he jacks himself, staring into his brother's eyes. 

Sam finally has his pants off and he straddles Dean, leaning down to kiss him, his cock lying heavy and leaking between them. Dean stops stroking himself, pulls out of the kiss and makes sure Sam is looking at him. Then he takes the hand without the mark and thrusts it in the cooling pool of blood under him, pushing it and sliding it until it’s covered in sticky, coppery red. He holds it up so Sam can see it, and fairly sure that Sam is about to lick it off his fingers, slips it in between them, wrapping the bloodied hand around both their cocks. 

Sam seems to snap, thrusting hard into his brother’s hand with abandon. He captures Dean’s other arm, licking and biting at The Mark there with an animal noise...the effect is instantaneous; both of them thrusting in sync, feeling each other’s pleasure as well as their own, one person split into two. They rut together, Sam’s mouth locked on Dean’s arm, until they howl in unison, the feedback of each other’s orgasm bouncing back and forth, over and over until Dean feels like it might never stop. 

Of course it does, but it seems to knock them out for a short time. When Dean comes to, Sam is dressed and watching him. Dean feels….crusty. Dried blood is literally everywhere. His hair feels crunchy with it. Sam has pulled Dean’s pants up and moved him out of the blood pool at least. He creaks his way up to a sitting position. 

“Fuck, barn floors are not a great place to pass out on.” Gingerly, he rubs his neck and then cracks it, then his arms and his back. 

Sam is still looking at him, his expression muddy. Dean sighs. 

“Please don’t.” he says quietly. Vulnerable. That’s the expression. It’s how Dean feels too, but he’s not going to be a huge girl about it. 

“Dean, this wasn’t…” Sam starts, but trails off. 

“Safe? No, no it was not. We should probably not fuck in pools of blood in the future. Too late now though.” Dean sighs. “I am not getting back to the hotel like this. I’ll get arrested.” 

Sam is fucking _looking_ at him again. “What?” he snaps. 

“In the future?” Sam fidgets. 

Dean gets all the way up off the floor, which is a fun experience, and goes over to Sam, crouching in front of him and looking in his eyes. “Yes, Sam. I’m not ever going to stop wanting you, and I think it’s pointless to try to walk this backwards. Am I thrilled? No. It’s wrong on so many levels, but…” he shrugs . 

“If loving you is wrong, I don’t want to be right,” He says, deadpan. Sam barks out a startled laugh, rolling his eyes and pushing at Dean’s shoulder. He grins, standing and pulling at Sam so he gets up too. 

“Let’s figure out how to get me back to a shower without being strip searched by a cop named Bubba. But first, we can’t leave the barn like this. ” 

Sam slings his arm over Dean and they walk over the corpses and out of the barn. Sitting on the trunk of the car and watching the barn burn with his brother, Dean thinks that he hasn’t felt this happy or this clear headed in years.


End file.
